Genes linked to Smoking Addiction

I am taking Critical Thinking and I read an article for this class that I found to be quite interesting. This article explains that new studies are coming out that connect genetics to nicotine addiction and lung cancer. "Scientists say they have pinpointed a genetic link that makes people more likely to become hooked on tobacco." (AP, 2008) is the claim I chose to look at in this article. The grounds for this claim that were identified in this article include studies from three separate teams of scientists around the world who have made a biological link to the addiction of smoking/nicotine. Another ground identified by the author is that these studies will show how smoking and our genes work together ultimately causing cancer. The warrants or 'so what' of the article(Memering and Palmer, 2006) include that finding this genetic link will increase the success of stop smoking programs in the future. The author also warrants that this scientific find may help us solve some of things that cannot be explained by environmental factors including chain smoking and lung cancer(AP, 2008).